1. Field of the Invention
The present invention relates to a power-supplying apparatus mounted on a sliding structure such as a sliding door of a vehicle for constantly supplying electricity to such as auxiliaries of the sliding structure.
2. Description of the Related Art
FIGS. 5 to 6 show an embodiment of a conventional sliding door (for example, refer to Japanese Published Patent Application No. 2001-354085).
This power-supplying apparatus 40 is installed on a sliding door 1 of a vehicle, and includes a protector 142 having a base and a cover (not shown) made of synthetic resin for receiving a wiring harness 143, and a metallic flat spring 144 assembled inside the protector 142 for urging upward the wiring harness 143.
The protector 142 is composed of a substantially semicircular part for receiving the wiring harness 143 and a slim extended part extended from a rear of the semicircular part, and has a vertical base 149, a round wall 150 disposed along a top end of the base 149, an oblong lower opening 145 for extending the wiring harness, and a front opening 151.
The protector 142 is vertically interposed between a metallic door panel 152 and a door trim made of synthetic resin (not shown). The wiring harness 143 is curved horizontally at the lower opening 145, arranged to a vehicle body 147, and fixed to a holder (not shown) at the vicinity of a step 148. Further, the wiring harness 143 is arranged into an inside of the sliding door through the front opening 151, and connected to the auxiliaries at the sliding door or a harness with connectors in order to constantly supply electricity.
The wiring harness 143 is made of a plurality of electric wires covered by a flexible corrugate tube made of synthetic resin. The corrugate tube is made by arranging alternately circular furrows and ridges. The wiring harness 143 is extended from the front opening 151 to a harness holder at the vehicle body 147.
As shown in FIG. 5, at almost fully closed state of the sliding door 1, the wiring harness 143 is pulled backward and bends the flat spring 144 downward. At a half-open state of the sliding door, the wiring harness is about to slack downward, but urged upward by the flat spring 144 to absorb the slack. As shown in FIG. 6, at almost fully open state of the sliding door 1, the wiring harness 143 is pulled forward and bends the flat spring 144 downward.
However, there is a problem that a space for components and the auxiliaries in the sliding door is reduced, because a conventional structure of the power supplying apparatus is to lift the wiring harness 143 with the flat spring 144 for absorbing the slack, and especially when an open/close stroke of the sliding door 1 is large, a height of the protector 142 should be large. Further, the conventional structure needs the metallic flat spring 144 and a bracket for fixing the flat spring 144, and resultingly a cost of the power-supplying apparatus is increased. Further, a lot of time is needed for fixing the flat spring 144.
Therefore, Japanese Published Patent Application No. 2005-20895 discloses a power-supplying apparatus which does not use a flat spring for preventing an enlarged protector, and a loop part is openable by a resiliency of a wiring harness with a harness guiding member, so that a height of the protector can be lower than that of the conventional protector, and a flexibility of arranging components in a sliding door is increased.
However, in the power-supplying apparatus of Japanese Published Patent Application No. 2005-20895, a resilient member such as a spring is needed to be used for urging obliquely downward a second guiding roller composing a harness guiding members. Because the resilient member is contracted when the sliding door is fully open, a pulling force to the wiring harness is increased. Thus, the wiring harness may be broken. Further, a structure for fixing and sliding guiding rollers composing the harness guiding members is needed. Therefore, a structure of the power-supplying apparatus becomes complex, and a cost of the power-supplying apparatus is increased. Further, an assembling work of the power-supplying apparatus becomes difficult.
Accordingly, an object of the present invention is to provide a power-supplying apparatus for a sliding structure which makes a structure thereof simple, allows a load to a wiring harness to be reduced, so that a protector can be downsized.